Drainage-casing.



A. SMITH.

DRAINAGE CASING.

APPLICATION FILED JUNE 2, 1911.

I Patented May 20, 1913.

H W 1 1 A 1 W1 1 1 h I i 14 11111111., 1 1.1-, 1 1 11111W111M 11 aQ/woa Roma ANDREW sm'rn, or SAN Marne, cAL1ron rA, assIe on To smirn" METAL reareharms company, on SAN MATEO COUNTY, cALIronNIA.

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Specification 01 Letters Patent.

ing. is a specification in such full'and clearterms'as will enable those skilled inthe art to construct and use the same. 4 1 This invention relates to a new, and 1m proved well-or drainage casing, and itsob j ect is to'produce metal'plates having a inrality of narrow slots therein to prevent the ingress of fine materials, such as sand, into the inside of the casing. Y I

Another ob'ect of-the invention is to produce perforated metal for well casing or-formeral of reference is applied to the same portion throughout the several views,'-.Figure 1 is' a side elevation of aportion of well casing slotted in the manner herein described, Fig. 2 is a cross-section of such a casing on the line 2-2 of Fig. 1, Fig. 3 is a plan of a portion of a metal plate perforated in the manner herein described, Fig. 4 is a side elevation of the perforated plate shown in Fig. 3, Fig. 5 is a sectional view of the plate shown in Fig. 3, Fig. 6 is a vertical section on the line 66 of Fig. 3.

The numeral 1 represents a portion of a well casing which has a series of slots as indicated at 2, there being any desired numthan the thickness .of the sheet not beingstrong enough to stand the work. Therefore, to produce the slots herein described, a punch must be usedof such extent as to have the necessary strength to enable it to withstand repeated operations. This extent in the smallest dimension is somewhat I greater than the thickness of the plate to be punched, as for example, with a. quarter- PatentedMay 20,1913. Application'filed June 2,1911. Seria 1-No.630,888. i

inch plate a punch one-half inch wide would be ample .to withstand the severe\ usage to which it is subjected. Since it is desired to produce a c'h'eap' casing in a single operation, a portion. of the metal punched is moved but, slightly more than one-half the thickness of the metal plate,-the" metal between the slots being shearedand punched alternately in opposite directions, thus forming a slot with amoveinent in the aggregate slightly greater than the thickness of the plate 'inwhichthe slo'tsare formed.

In this operation the entire band of metal across aseriesof parallel slits is f orcedjal 'ternately in opposite directionsand the plate" is thereby contracted a suflicient amount to allow the projections to extend. beyond the plane of the plate. without =stretching or distorting the metal of the projectionswhich thus remain substantially the thickness of the plate throughout their t6- the ends of which'are roundedjto prevent the cutting of the metal at the ends of the punch, it will be possible to distort themetalof theplate as shown at 4 and'6, one of said.

set of projections 4 beingraised" upwardly while the other set 6 is pushed downwardl Theopenings in the plates may be ma e of any desired width, although of'course for I use as well casing and for use as tiling, it is" contemplated that the slots formed-will be s'ufliciently small to preventthe in ess of fine sand. Anadvantage of this orm. of

well casing is that the7slots formed have sub stantiall smooth walls, so that there is very litt e chance for rust to set in, and the slots may bemade of a given thickness with mathematicalaccuracy since the opening is exactly' letermined by the depth of the male and female dies. A..further advantage'following from the factthat the "meta-lie cut so smoothly, lies in the fact that it is possible to galvanize the casing after the slots have been formed therein without closin openings, as is liable to occur when t e'a-ttempt is made to galvanize the so-called the cracked casing in -which rough points project from each side f the openings formed. I

While I have shown the sheared and v punched portionsarranged in annular rows,

with the slots extending longitudinally of the casing, it is obvious that the sheared portions may be arranged in staggered fashion or in any othermanner, and also that said sheared portionsand slots may exv tend transversely of the casing or in any inner surfaces of the projections upon one direction that may be desired.

Having thus described my invention what I claim as new and desire to secure byLetters Patent of the United States, modifica side lying within the plane of the sheet.

2. A drainage casing comprising a sheet of metal having aplurality of slits formed therein by shearing the metal of the plate to form projections whose planes are paral lel with the surface of the plate, the outer in the plane of the sheet, substantially as described.

3.. A drainage casing comprising a sheet metal body .having' a plurality of parallel slits formed therein by shearing the metal of the plate to form projections extending alternately in opposite directions, each projection being substantially the thickness of the plate throughout its extent and comprising the metal bet-ween adjacent" slits, the main body ofeach of said projections being straight and parallel with the plane of the plate to thereby form slots between the adjacent edges of the oppositely extending projections which are ofuniform width.

In testimony whereof I have hereunto set my, hand this 23d day of May A. D. 1911, in the presence of the two subscribed wit- Witnesses:

C. P. GRIFFIN, HENRY B. LISTER.

AN RE SMITH. 

